Comment by PeterisP

Comment by PeterisP 10 months ago

21 replies

If someone would do the thing-to-be-detected (e.g. accessing CSAM) every day, then that 0.14% probability of detection turns out to be 40% for a single year (0.9986^365) or 64% over two years, so even that would deanonymize the majority of such people over time.

sigmoid10 10 months ago

That assumes you could run thousands of malicious tor nodes for several years without being detected. Unless you have vast resources and time, this is unlikely.

  • alasdair_ 10 months ago

    My point is that it doesn't require "vast resources". A VPS is $5 a month. A thousand of them would be in the disposable income budget of a single FAANG engineer never mind a nation state.

    Pay people on Fiverr to set them up for you at different ISPs so that all the setup information is different. You can use crypto to pay if you want anonimity (this is actually the main reason I used to use bitcoin - I'd pay ISPs in Iceland to run TOR exit nodes for me without linking them to my identity).

    This isn't a difficult problem. A single individual with a good job could do it.

    And sure, each connection only has a very small chance of being found, but aggregate it over a year or two and you could catch half of the users of a site if they connected with a new circuit one time per day.

    I honestly can't see why a nation state or two hasn't already done this.

    • jiveturkey 10 months ago

      > A VPS is $5 a month.

      With insignificant data caps. To get the data needed I believe you're looking at a couple hundred a month, to start.

      • judge2020 10 months ago

        Running exit nodes is also likely to result in getting booted from most VPS or even bare metal providers, maybe unless you BYOIP.

        • AstralStorm 10 months ago

          And if you BYOIP, and run a large node, Tor volunteers will try to contact you and verify...

  • worldsayshi 10 months ago

    But it doesn't seem unfeasible for a state actor that wants to track their population then?

    • ziddoap 10 months ago

      The comment that spawned this chain starts with:

      >Let's say I as a private individual

      • worldsayshi 10 months ago

        Yes that's why I said 'but'. It still seems relevant to the discussion and I wasn't aware that such attack was possible.

  • Spivak 10 months ago

    But given the attack is just logging the cleartext at the ends how are you going to detect that the servers are malicious?

  • AndyMcConachie 10 months ago

    What detection? A malicious node is only different from a non-malicious node because all the traffic is being logged. If that's our definition of a malicious node in this case then there is no way to detect one.

  • mistercheph 10 months ago

    I can't think of anyone with vast resources and time that would want to deanonymize cybercriminals

    • colechristensen 10 months ago

      Outside of 3 letter agencies which is obvious, I have known people who would do this for fun or whatever other personal motivation.

      A lot of "hacker" mentality projects involve putting a tremendous amount of effort into something with questionable utility.

      People climb mountains because they're there.

    • sigmoid10 10 months ago

      Top commenter specifically asked about himself.

bawolff 10 months ago

That is why in tor it picks a specific guard node and sticks with it. To prevent this kind of attack where you change nodes until you hit a bad one.

  • immibis 10 months ago

    The attack Germany is thought to have actually used was to flood the network with middle nodes and wait until the victim connects to their middle node. Then, it knows the guard node's IP. Then, it went to an ISP and got logs for everyone who connected to that IP.

    • posterboy 10 months ago

      technicly this is the only comment in this chain that is relevant to the featured article, but it's technicly so incomplete that it's almost wrong, I can tell from having read the thread and knowing next to nothing else about how TOR works.

      They don't have plausible evidence to subpoena the guard node if a middle node only sees encrypted traffic. They would also need to control the exit nodes which communicate with the target's host or they simply control the host as a honeypot.

      • immibis 10 months ago

        Because the victim was an onion server, they could make it generate new connections at will. They used timing correlation to determine their node was the middle node for their connection.